CHANGPING, CHINA -- After bulking up its armed forces with new missiles and other advanced weaponry, China recently invited U.S. and other foreign military officials to inspect a less bellicose side of the People's Liberation Army: a fleet of bulldozers.

Through clouds of smoke generated to simulate the look of a war zone, a PLA engineering brigade showed off its earthmovers, mine-clearing gear and other nonlethal hardware at a base north of Beijing.

The display, put on shortly after President Obama left Beijing last month, represented what China sees as an important part of its answer to a question that shadowed Obama's eight-day Asia tour: How will China use the formidable power generated by its relentless economic growth?

The engineering unit that staged the show is spearheading China's growing involvement in international peacekeeping, a cause that Beijing for decades denounced as a violation of its stated commitment to noninterference in the affairs of other nations but that it now embraces.

Today, about 2,150 Chinese military and police personnel are deployed in support of U.N. missions. They serve around the world, from Haiti to Sudan.

A 'peaceful rise'

Though the peacekeepers represent only a fraction of the PLA's more than 2 million soldiers -- and account for a minuscule part of the Chinese military budget -- China's enthusiasm for peacekeeping signals a clear desire to project an image as a responsible and peaceable great power. And even if, as some experts say, China's total military spending is perhaps double the stated amount, it is still less than a third of the United States' basic military budget, which excludes spending toward the wars in Iraq and Afghanistan.

When Germany and later Japan emerged as military powers on the back of surging economies more than a century ago, a calamitous reordering of the world order followed. China, pursuing what it calls a "peaceful rise," points to the PLA's peacekeeping activities as evidence of its benign intentions.

But while increasingly willing to let its soldiers don the blue helmets worn by U.N. peacekeepers, China has shown little enthusiasm for the U.N.-sanctioned mission that currently matters most to Washington -- the war in Afghanistan.

Wariness toward NATO

When the United States wanted to fly a group of Mongolian trainers to Afghanistan in October, China objected to letting the aircraft go over its territory. Beijing eventually gave the flight a green light -- but only after ammunition was taken off the plane, according to a U.S. official familiar with the matter.

Though authorized by the United Nations, the Afghanistan mission is led by NATO, an organization China views with deep wariness. Beijing blames NATO for the 1999 bombing of the Chinese Embassy in Belgrade during the Kosovo war.

China's shock at NATO's military campaign in the former Yugoslavia helped prod Beijing into playing a bigger role in U.N. peacekeeping, said Bates Gill, director of the Stockholm International Peace Research Institute and co-author of a recent report on China's peacekeeping activities. China, he said, is "highly unlikely" to send soldiers to Afghanistan to help "what is essentially a NATO operation, albeit with a United Nations blessing."